In recent years, the Internet has grown rapidly. Its application spans a wide variety of fields. As a result, the enhancement of wireless network environments is required to realize the Ubiquitous communication.
MobileIPv6 has been standardized by IETF (Internet Engineering Task Force) as a communication protocol for wireless networks. It is regarded as an important component of the infrastructure that will realize ubiquitous communication. Moreover, for the speedy adoption of MobileIPv6 protocol, an efficient and reliable management framework is necessary.
In current Internet environments, SNMP is employed as a standard protocol for network management. An SNMP network management system comprises of a Manager system (Manager) and one or more managed systems (Agents). A Manager manages the network configuration, traffic, fault, performance and other aspects of the network. The Agent, normally installed on the managed device, maintains configuration information, traffic information, real-time status information, event information, and other network management information in a virtual store called the MIB (Management Information Base). SNMP is the transport protocol used by a Manager to obtain management information from the Agent's MIB, The Agent services requests related to MIB data from the Manager on-demand. The Manager manages the network devices within its management domain based on the MIB data obtained from Agents.
There are mainly two ways to collect network management information in traditional wired network environments described in patent document 1 and patent document 2, respectively.
In patent document 1, when a Manager collects MIB data from an Agent, it collects only the part that has changed. This can reduce the transfer data size and the data collection time, and results in a reduction of network management traffic.
In patent document 2, an Agent measures the operational status of managed devices at regular time intervals, appends time-stamp to the measured data, and stores the data in a table. A Manager collects data from an Agent in one of two data-collection modes. In the all-data-collection mode the Manager requests for all the data in the data table. The Agent sends all the data to the Manager in this case. In the latest-data-collection mode the Manager requests for the latest data record in the table and the Agent sends the latest record in the corresponding data table to the Manager. In this approach the Manager can collect large volumes of MIB data, which may be sampled at very small intervals without shortening the polling-interval. This enables the Manager to monitor and analyze small changes in the network device.    It is Japanese Patent Laid-Open No. 2000-066978 bulletin [patent document 1]    It is Japanese Patent Laid-Open No. 2002-278854 bulletin [patent document 2]